The present invention relates to an imaging system with an integral cover sheet.
Photosensitive imaging systems employing microencapsulated radiation sensitive compositions are the subject of commonly assigned U.S. Pat. Nos. 4,399,209 and 4,416,966 as well as co-pending U.S. patent application Ser. No. 320,643, filed Jan. 18, 1982. These imaging systems are characterized in that an imaging sheet including a layer of microcapsules containing a photohardenable or photosoftenable photosensitive composition in the internal phase is image-wise exposed to actinic radiation. In the most typical embodiments, the photosensitive composition is a photopolymerizable composition including a polyethylenically unsaturated compound and a photoinitiator and is encapsulated with a color former. Exposure image-wise hardens the internal phase of the microcapsules. Following exposure, the imaging sheet is subjected to a uniform rupturing force by passing the sheet through the nip between a pair of pressure rollers.
Commonly assigned U.S. Pat. No. 4,440,846 discloses a self-contained system in which the encapsulated color former and the developer material are co-deposited on one surface of a single substrate as one layer or as two contiguous layers. Upon passing the self-contained copy sheet through pressure rollers in contact with the copy sheet, the microcapsules image-wise rupture and release internal phase whereupon the color former migrates to the developer material where it reacts with the developer material and forms a colored image.